Open Fracture Gustilo Classification

Stratifies injury severity based on type of trauma and wound characteristics.

In the text below the tool you can find more information on the fracture grades and on the original study.

The Gustilo classification for open fracture accounts for the mechanism of trauma, extent of soft tissue injury and contamination, to stratify wound severity. The grades used, as they increase in severity, are I, II, IIIA, IIIB and IIIC.

This is based on the Gustilo System which was the first model to define differences in open fractures and to discriminate between mild and severe injuries.

The original retrospective study was led in 1976, by Gustilo and Anderson, on a cohort of 673 patients with open fractures of the long bones.

The analysis found that infection rates decreased in time because of changes in the management of open fractures.

The study also makes recommendations in regard to the antibiotic use, depending on injury severity.

  ■ Low energy mechanism;
  ■ Less than 1 cm in length;
  ■ Minimal contamination.
  ■ Moderate energy mechanism and soft tissue damage;
  ■ Between 1 cm and 10 cm;
  ■ Moderate contamination risk.
  ■ High energy mechanism, extensive soft tissue damage;
  ■ Over 10 cm in length;
  ■ Vascular repair and/or have been open for 8 hours prior to treatment;
  ■ Very high degree of contamination.
  ■ IIIA adequate periosteal coverage;
  ■ IIIB inadequate periosteal cover with bone damage and soft tissue damage;
  ■ IIIC associates with arterial injury and extensive soft tissue laceration.
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Gustilo classification explained

This is an injury severity classification system addressed to open fractures (in the original study, OFs of the long bones).

OFs are defined as broken bones in communication with the environment through the skin after trauma.

Gustilo classification accounts for mainly three factors in stratifying the injury severity:

■ Amount of energy in the injury mechanism;

■ The extent of soft tissue injury;

■ The extent of contamination.

The trauma energy varies from low (simple fractures, stabbings, gun wounds) to high (in high speed trauma). This factor is used in the Mangled Extremity Score too.

The extent of damage to the soft tissues varies from minor to very severe.

The extent of contamination analyses the degree of communication with the environment and possible risks of presence of bacterial cultures and infection.

Progression from the least severe stages (I and II) to the most severe ones (IIIA, IIIB and IIIC) occurs when all the three factors are severe and there is bone damage and/ or vascular injury.

The table below describes the severity stages and their characteristics:

Gustilo type I III IIIA, IIIB, IIIC
Trauma energy Low Moderate High
Wound size <1 cm >1 cm >10 cm
Soft tissue damage Minimal Moderate Extensive
Contamination Clean Moderate Extensive
Fracture pattern Simple fx pattern Moderate comminution Severe comminution
Periosteal stripping None None Present
Neurovascular injury Normal Normal IIIA, III B – normal
IIIC – exposed fracture with arterial damage
Skin coverage Local coverage Local coverage IIIA – local coverage including
IIIB – requires free tissue flap or rotational flap coverage
IIIC – requires flap coverage
Average time to union 21 – 28 weeks 26 – 28 weeks 30 – 35 weeks

The classification of the fracture is done rapidly, however frx findings must be accounted too.

The Gustilo system reduces unnecessary time waste during diagnosis (wait for frx) so that treatment is initiated as soon as possible (very important when contamination risk is high). This means that usage of this model also reduces the chance of complications.

The Gustilo classification is used in ERs along with other emergency scoring systems, such as the Revised Trauma Score.


About the study

Gustilo and Anderson conducted a retrospective analysis on 673 cases of open fracture of the long bones. These included tibia and fibula, femur, radius, ulna and humerus fractures.

It was found that infection rate decreased from 12% (1955-1960) to 5% (1961-1968) and this was correlated with fracture management improvements.

In a further study between 1969 and 1973, a cohort of 352 patients were managed differently depending on the fracture stage they were assigned, according to the model.

In 158 of patients, initial wound cultures found bacterial growth and the infection rate was 2.5%.

The Gustilo system has been criticised for not enough interobserver reliability in some studies.


Antibiotics use in open fractures

The following table introduces the antibiotic recommendation for open fractures, depending on the Gustilo grade:

Gustilo grade Antibiotic therapy
I and II 1st generation cephalosporin
III 1st generation cephalosporin + aminoglycoside
This is traditionally recommended, but there is no evidence in the literature
III with farm injury or bowel contamination 1st generation cephalosporin + aminoglycoside + PCN

Original source

Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am. 1976; 58(4):453-8.

Other references

1. Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma. 1984; 24(8):742-6.

2. Kim PH, Leopold SS. In brief: Gustilo-Anderson classification. Clin Orthop Relat Res. 2012; 470(11):3270-4.

3. Brumback RJ, Jones AL. Interobserver agreement in the classification of open fractures of the tibia. The results of a survey of two hundred and forty-five orthopaedic surgeons. J Bone Joint Surg Am. 1994; 76(8):1162-6.

4. The Management of Severe Open Lower Limb Fractures (2009). British Orthopaedic Association.

Specialty: Traumatology

Objective: Evaluation

Type: Classification

No. Of Items: 4

Article By: Denise Nedea

Published On: June 2, 2017

Last Checked: June 2, 2017

Next Review: June 2, 2023